JANUARY 22, 1925
THE AEROMARINE EO SPORT FLYING-BOAT
A LITTLE while back the Aeromarine Plane and Motor Co., of
Key Port, N.J., completed a small metal-hull flying-boat
possessing several very interesting features, and we give
below a description, together with illustrations, of this
machine.
This flying-boat has been specially designed for Mr. E. D.
Osbom, who was formerly associated with Aeromarine
Airways, to take the place of his older Aeromarine Model 44
flying-boat. While the new model EO was built around a
smaller engine in order to reduce petrol consumption and
opening of throttle, and with pilot only was off the water in
15 seconds, and with two passengers in 20 seconds. As a
large-size air-screw was fitted, the engine speed did not
exceed 1,390 r.p.m. (corresponding to 72-5 h.p., according
to maker's power curve).
Tests over the speed course, with two up, showed a high
speed of 73-5 m.p.h., and the speed at minimum throttle
setting (1,010 r.p.m.) was 40-5 m.p.h.
The Aeromarine EO is a tractor biplane having a lower
plane of considerably smaller chord staggered some way back
THE AEROMARINE MODEL EO SPORT FLYING-BOAT: Front and side views and, inset, in flight.
is fitted with a 70-80 h.p. Anzani 6A3 engine. .-,.
give improved maintenance, it was required to carry the
same aseful load and have the same—if not better—perform-
ance as the older boat. It was also required that special
consideration should be given to the question of safety, as
this was rightly held to be an important factor should this
model be put into production (as it probably will), not only
for sport purposes, where the owner will also be the pilot,
but for training work as well.
Special attention was to be given to the matter of balance
with and without passengers, and with power on and off—
a somewhat troublesome problem as far as flying-boats are
concerned. Designs for the EO, embodying these require-
ments, were completed early last year, and the first tests
were made, Mr. Osborn piloting himself, in J une last. During
these tests, the machine fulfilled all the requirements called for,
especially as regards balance. Tests were made with pilot
only, with one and with two passengers, and the balance was
found satisfactory in each case, while the flying qualities
seemed to be but little affected by the amount of load carried.
In all tests the boat was on step in four or five seconds after
of the top plane—below the trailing edge of the latter. The
wings are of wood and fabric construction, while the engine,
petrol and oil tanks, with all accessories, are mounted in an
aluminium-alloy nacelle supported on struts above the hull,
to which struts are also hinged the top wings, All nacelle,
interplane and tail struts are of streamline-steel tubing.
Several advantages are claimed for the tractor-screw
arrangement, most important of which being the question of
safety. In this respect there is little danger of anything
from the cockpit fouJing the air-screw, while in the event of a
crash the danger of the crew being pinned under the engine
is considerably minimised. Incidentally, the position of the
cockpit far back in the EO also makes for safety in the
event of a crash. Another advantage is that in the case of
any leakage in the petrol system there is less danger of the
petrol falling on the hot exhaust or engine, and thus causing
a fire.
Apart from the question of safety, however, the tractor-
screw arrangement allows for better cooling and improved
efficiency and reliability in consequence, while it also enable*
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